Following the tragedy, near Dereham, Mid Norfolk MP George Freeman pledged to write to a government transport minister to say enough is enough and stress the urgency for the A47 to be prioritised for investment.

Yesterday’s east-bound crash between Draytonhall Lane and the A1075 junctions and a second crash at North Tuddenham two hours later come as the EDP, MPs and local organisations are campaigning for the A47 to be fully dualled and for other safety measures to be made.

Mr Freeman, who called a debate in parliament last week about the future of the road, said that Norfolk had waited for too long for improvements, and it was now the time for action.

He said: “This tragedy is a shocking reminder of the huge human as well as economic cost to Norfolk of the A47 in its current state.

“But this has gone on for too long. The A47 has for years been one of the most dangerous roads in our region and hardly a month goes by without a serious accident and tragedy like this today.”

A Norfolk police spokesman said the woman killed in the crash was aged in her 50s.

The spokesman added: “The female passenger in one of the cars sadly died at the scene, whilst the driver of this car was seriously hurt although her injuries are not considered life-threatening.

“The male driver of the second car has been taken to hospital and is critically injured.”

The two women were travelling in a green Peugeot 406, while the man in the second car, who was in his 20s, was driving a red Skoda Felicia.

He was initially taken to the Norfolk and Norwich University Hospital, but was yesterday afternoon moved to Addenbrookes’s Hospital, in Cambridge.

Police are appealing for three witnesses to come forward, specifically the driver of a small black Peugeot hatchback car which was seen driving erratically towards Norwich and failed to stop at the scene of the crash, which happened at 10.30am. It overtook the green Peugeot and a white long flatbed lorry.

They also want to hear from the driver of the white lorry, with something fluorescent on a whing mirror, which failed to stop, as well as a tall, slim man who spoke to the driver of the green Peugeot after the crash.

Chloe Smith, MP for Norwich North, said: “Clearly these are very tragic circumstances, and my first thoughts are with the families.

“However, the road does need improvements which will make it safer, as well as opening up opportunities for households and businesses to get around.”

On Mr Freeman’s message to government, she added: “This is another united Norfolk campaign to secure the kind of improvements that will help our economy in Norfolk as well as keep people safer.”

Keith Simpson, MP for Broadland, said that the latest tragedy demonstrated the need for improvements, and that the case for the A47 had been forcefully put by Norfolk MPs to Stephen Hammond, the roads minister.

“There have been a series of accidents on the A47 in the last few months, and this highlights to everybody the need to get on with it,” he said.

“It’s tragic for the people involved but this is more ammunition as far as we are concerned in bringing more pressure on the minister.”

The second accident, at North Tuddenham, happened just after 12.30pm when a car rolled on to its roof causing a large stretch of the A47 to be blocked for several hours.

Two fatal crashes on the A47 at the end of December claimed the lives of five people. Three people were died following a crash at Wendling on Christmas Eve and two young sisters were killed when the car in which they were travelling left the road near Wisbech on December 27.

The latest campaign for the road emphasises both safety and a potential multi-million pound boost to Norfolk’s economy over 20 years, including 10,000 jobs, a £390m annual economic boost and up to £800m of private investment.

The transport minister Stephen Hammond said last week that the A47 is “ideally placed” to attract government money for a major upgrade as early as 2015, and Mr Freeman said he would be writing to Mr Hammond to stress his point.